It believes that the miniature devices were planted on the contractors while they were visiting Canada and it ended up in their wallets with all that fairly useless foreign money you get when you are on holiday.
A Defense Department spokesman said that the coins could be used to track the movements of people personnel dealing in sensitive military technology.
While many spies might be wondering why US consultants are spending a lot of time at the back of the sofa, a former CSIS officer turned consultant David Harris thinks that the coins could tell agents all they need to know.
Speaking to the Toronto Star, Harris said that the coins could tell where the individual was going, to what meetings and with whom. The more covert or clandestine the activity in which somebody might be involved, the more significant this kind of information could be, he said.
However Chris Mathers, a security consultant and former undercover Mountie said the whole idea was daft.
Besides the fact that the coins' range was limited, a coin could end up into a coke machine or in a parking meter. As Mathers points out, you give something with a transmitter that a target is going to spend he might only have it for an hour.
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